Analisi sperimentale e numerica di alcuni aspetti della dinamica degli ammassi granulari

In the present work some aspects of the dynamics of granular masses with reference to phenomena such as debris flows, dense snow avalanches and rock avalanches have been studied. The issue has been addressed experimentally by tests carried out at the Laboratory of Hydrogeology of the University of Padua. The results of the experimental tests have been used for the calibration of a particle numerical model, built to simulate the dynamics of dry granular masses. The experimental tests have been realized by releasing on the upstream plane of a channel formed by two tiltable planes, a fixed amount of granular material. The slope of the downstream plane has been set in order produce the stopping of the material. Granular materials different in shape, specific weight, particle size distribution have been used. The evolution of the laboratory tests have been investigated by using a hardware and software system for the three-dimensional photogrammetric survey, which allowed the reconstruction of the shape of the outer surface of the moving granular mass, at choosen instants of time. The used numerical model solves the dynamics of the granular mass describing the motion of the individual particles with the second dynamics motion equation. The physical parameter essential for the description of the choosen rheology is the friction angle between the granular material and the planes bottom, which has been experimentally determined for the various materials